DE102015106822A1 - Motor drive with high boost / sustain thrust ratios - Google Patents

Abstract

Motor drive, in particular rocket motor drive, which is driven by means of a solid propellant, comprising a booster drive and a sustain drive, characterized in that the sustain drive (1) in the boost motor (2) is arranged.

Description

The present application relates to a motor drive, in particular a rocket motor drive according to the main claim.

Advantageous embodiments are laid down in the subclaims.

The invention is based on drive technologies which have tube internal burners and front burners. The tube internal burners are also referred to as booster in German-speaking countries; The commonly used language term for the Stirnbrenner is also in German-speaking countries Sustainer.

The present invention is based on such boost / sustain motors, which are known in their basic structure. This type of propulsion combines two types of propulsion, especially for rocket engines, with the boost drivetrain providing high propulsion acceleration, while the Sustain drivetrain provides further continuous thrust at reduced thrust.

Such a boost / sustain drive is for example in the American patent US 4,015,427 discloses, from which the essential parts of the drive and, among other things, the type of fuel arise.

The Boost / Sustain motors, which are characterized by their construction and mode of operation through the use of a common nozzle for the boost and the sustain phase, can achieve maximum Boost Sustain thrust ratios of 6 to 8.

Another embodiment of such a drive system is in the European patent specification EP 0 184 014 B1 which relates to a propellant assembly for a solid rocket engine in which a cylindrical housing with a cylindrical main propellant and another igniter with a further ignition propellant and their spatial arrangements are disclosed in the housing.

The German patent DE 44 22 195 discloses an injection system for hybrid rocket engines in which an internal burner is combined with solid fuel and a liquid component, namely an oxidizer.

Furthermore, the present application is based on rocket engines with a dual-pulse technology, which are used for example in the air defense missiles of the applicant.

The core element of a double pulse motor is the ability to ignite two pulses separately depending on the respective mission requirements. Technically, this is achieved by a pulse separator which shields two separate propellant charges in a combustor. As a result, a variable ignition delay is possible depending on the mission requirements. In this technology, there are two separate propellant charges in a combustion chamber. The separation of the propellant charges is carried out by the pulse separator. There are two independent ignition systems available. The individual pulse motors thus have different Abbrandcharakteristiken and are sequentially, that is arranged in line. This technology uses a common nozzle.

This state of the art of both types of drive boost / sustain and double pulse device has as a common feature the use of a common nozzle. The achievable boost / sustain thrust ratios are limited by the boost / sustain pressure conditions. It would be necessary - if you want to achieve high thrust ratios - very large different mass flows. But you can not handle this with an engine and a nozzle.

In this case, upper pressure limits, which are caused due to the combustion chamber loading and combustion chamber construction and correspond, for example, to an operating pressure of 200 bar, apply to the boost phase. As a result, the sustain propellant burns to a first approximation at a pressure that meets the required boost / sustain thrust ratio. So, for example, at a ratio of 10 in the said example of an operating pressure of 200 bar a sustain pressure of 20 bar result. At such relatively low pressures, the achievable powers, i. the specific impulse, low. On the other hand, there is a risk that the propellant ignites bad or even stops the combustion.

The efficiency of twin-pulse motors is high even with the use of complex pulse separation devices, such as, e.g. Burst membranes that physically separate both "in line" single pulses are limited; no big Boost / Sustain thrust ratios can be achieved. The use of bursting membranes for pulse separation leads to expensive solutions. In addition, they increase the complexity of the engine and increase the engine mass. Furthermore, the opened bursting membrane must remain connected to the rocket motor without mechanical parts flying through the nozzle and damaging them, as well as the thermal insulation of the empty-fired first-pulse combustion chamber.

Based on these characteristics of boost / sustain motors and double pulse motors, the present invention is based on the technical problem of significantly increasing boost / sustain thrust ratios, with ranges from 10 to 25 or even greater being achieved.

Furthermore, it should be possible to dispense with the use of expensive pulse separation devices.

Furthermore, it should be ensured that the propellant, which is a solid propellant, is well flammable and the combustion does not threaten to stop.

In addition, the engine mass should be lower compared to this prior art. Another goal is to reduce complexity.

Another desirable aspect is to improve the thermal situation, especially during the long lasting sustain phase, by providing improved thermal insulation against components typically attached to the exterior of the missile, such as: mechanically fastened planks or guiding systems, so-called strakes or fins, electrical, electronic fin actuator systems, batteries and cables or other components is achieved.

Another object of the invention is to individually fire the boost and sustain motors via two separate igniters and two independent igniter signals, or to ignite both motors together via two separate igniters and a common igniter signal.

In particular, a cost-optimized solution should be made available.

These various objects are achieved by means of a device according to the main claim. Preferred embodiments are disclosed in the subclaims.

An essential aspect of the invention is to decouple the boost drive and the sustain drive functionally and effectively, but to use the spatial configuration, for example, a housing for these drives and insert the Sustain engine in the boost engine, so both engines sort of nesting. The lower thrust sustain engine is inserted into the higher thrust boost engine, where the insertion may be insertion, insertion, or the like.

Furthermore, it is essential that the lower-thrust sustain engine be provided with its own smaller nozzle, while the boost engine also has its own nozzle. Thus, the two engines are directly decoupled from each other in terms of operating pressures during the boost and sustain phases.

This makes it possible to design the combustion chamber inside this spatial configuration weaker or designed so that the desired thrust is ensured. At a desired pressure then the engine burns off very efficiently. The outer boost engine may also be designed to run in an advantageous, preferably optimal range.

An essential aspect of the invention is therefore to couple these two engines each with its own nozzle or to provide. Both drives can therefore burn past each other in separate nozzles.

According to the invention, therefore, a high-performance integrated solid propellant engine, in particular a rocket motor, is provided. Within the housing provided for the drives, the boost motor is arranged in the outer direction. The boost motor has a freewheeling or also connected to the outer booster combustion chamber wall propellant, which is designed as a tubular inner burner with a relatively small Web.

Inside the booster, the Sustain engine with its own combustion chamber is arranged. The sustain drive has a preferably essentially free-standing front burner for sustain operation.

Both drives, ie motors, have their own gas pipe and their own nozzle. The nozzle of the sustain drive can preferably be structurally surrounded by the nozzle of the boost drive. In particular, in this case, two separate nozzle openings are provided.

The Gasleitrohr and / or the nozzle are preferably arranged concentrically to each other.

With this configuration, the combustion chamber pressures are completely decoupled from the boost / sustain thrust ratios.

The ignition of the two propellant charges is preferably carried out by means of a lighter, so that the Sustainer mitbrennt in the relatively short boost phase.

On the basis of the respective performance requirements for the two flight phases, a motor geometry can be effected in such a way that for example, the boost propellant length corresponds to the sustain propellant length.

In an embodiment according to this aforementioned configuration, it is also possible to use a single kind of fuel for the boost and sustain phases. This enables a mass and cost optimized design.

When choosing different fuels for the boost and sustain phase, of course, even greater flexibility in the boost / sustain design can be achieved.

By decoupling the operational combustion chamber pressures from the Boost / Sustain thrust ratios during boost and sustain, high Boost Sustain thrust ratios ranging from 10 to 25 or even greater can be set.

On the use of elaborate, used in double pulse motors Pulse separation devices can be dispensed with.

Further advantages are thermally due to the arrangement of the Sustainers in the booster: the air in the empty and external booster combustion chamber and in the booster Gasleitrohr serves as thermal insulation during the longer lasting sustain phase. This has significant advantages for components typically attached to the exterior of the missile, such as e.g. mechanical fastened strakes or fins, electric or electronic fin actuator systems, batteries, cables or other components.

The boost and sustain motors can be ignited simultaneously with an external signal, eliminating the need for complex signal controls and controls as previously required so that the sustainer burns in the relatively short boost phase.

The number of components is reduced, so that the weight of the corresponding overall device is reduced. This also means space-optimized advantages.

The invention will be explained with reference to the following embodiment.

1 shows a schematic diagram of the arrangement of the two drives in an axial longitudinal direction.

The solid rocket motor has a sustain motor 1 This is in the boost engine 2 arranged.

The boost engine 2 with the outside booster combustion chamber 30 has a freestanding or also connected to the booster combustion chamber wall propellant 3 ,

The inside of the boost engine 2 arranged sustain motor 1 has its own combustion chamber 10 , The sustain engine 1 includes a freestanding forehead burner 4 for sustain operation.

To the boost engine 2 closes a Gasleitrohr 5 at. To the sustain engine 1 closes a Gasleitrohr 6 at.

To the gas pipe 5 the boost engine closes its own boost nozzle 7 for the boost engine. To the own gas pipe 6 the sustain motor closes its own sustain nozzle 8th at.

The gas pipe 5 includes the Gasleitrohr 6 concentric. The respective Gasleitrohr leads the hot gas to the respective nozzle.

The nozzle 8th of the forehead burner 4 runs inside the nozzle 7 , The nozzles are designed concentrically, that is, the nozzle 8th runs inside while the nozzle 7 around the nozzle 8th arranged around.

The outer nozzle 7 is either as an annular nozzle or over several individual nozzle orifices, which are circumferentially around the centrally located nozzle of the Sustain engine (nozzle 6 ), executed.

By providing two separate nozzle openings one can adjust any power ratio of the two drives to one another.

The two aforementioned Gasleitrohre 5 . 6 connect the two combustion chambers 30 . 10 as well as the two drives 2 . 1 with the two nozzles 7 . 8th , By this configuration, available space can be used for other components, eg for one or more control units for control surfaces.

The ignition of the two propellant charges by means of lighters 9a . 9b so that the Sustainer burns in the relatively short boost phase.

The lighter 9a is assigned to the boost engine while the lighter 9b intended for the sustain engine.

In the one mode of operation, both lighters may be initiated by a common ignition signal. In another mode of operation, both lighters can be initiated separately from each other with a certain time delay.

Incidentally, the operation, the structure of the aforementioned components of the boost motor, the sustain motor, the solid propellant, the combustion chamber walls, the gas pipes and the nozzles are well known in the prior art and are therefore not described in detail in the present application. Their design and selection is at the discretion of the skilled person, which will take into account, among other things, the respective mission requirements.

LIST OF REFERENCE NUMBERS

1

Sustain engine

2

Boost engine

3

Propellant for boost engine

4

front burner

5

Gas pipe Boost engine

6

Gas duct Sustain engine

7

Nozzle boost engine

8th

Nozzle sustain engine

9

lighter

10

Combustion chamber for Sustain engine

30

Combustion chamber for boost engine

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4015427 [0005]
• EP 0184014 B1 [0007]
• DE 4422195 [0008]

Claims (7)

Motor drive, in particular a rocket motor drive, which can be driven by means of a solid propellant charge, comprising a booster drive and a sustain drive, characterized in that the sustain drive ( 1 ) in the boost drive ( 2 ) is arranged. Motor drive, in particular rocket motor drive, according to claim 1, characterized in that the sustain drive ( 1 ) a separate combustion chamber ( 10 ) and a freestanding forehead burner ( 4 ) for sustain operation. Motor drive, in particular rocket motor drive, according to one or more of the preceding claims, characterized in that the sustain drive ( 1 ) and the boost drive ( 2 ) each have their own Gasleitrohr ( 5 . 6 ). Motor drive, in particular rocket motor drive, according to one or more of the preceding claims, characterized in that the sustain drive ( 1 ) and the boost drive ( 2 ) each have their own nozzle ( 7 . 8th ) exhibit. Motor drive, in particular rocket motor drive, according to claim 4, characterized in that the two nozzles ( 7 . 8th ) are arranged concentrically with each other. Motor drive, in particular rocket motor drive, according to one or more of the preceding claims, characterized in that the operative pressures during the boost and sustain phase are decoupled from the boost / sustain thrust ratios. Motor drive, in particular rocket motor drive, according to one or more of the preceding claims, characterized in that the ignition of the two drive trains either via separate ignition signals to the igniters 9a and 9b or via a common ignition signal that both igniters ( 9a and 9b ) is initiated simultaneously.

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